Improvement in electro-magnetic alarms



'r1-tomas s. HALL, or sTAMroRD, Asstonon rro HALLS ELECTRIC ItAILwAY- s\wren .AND DRAWBRIDGE ,SIGNAL COMPANY, OF NEW HAVEN, CONNECTIGT.

Lem Parme No. 105,447, daad .my 1o, 1870.

`11s/tenenteMEM'-IN Emerso-MAGNETIC ALARMS.

f The Schedule referred te in these Lettera Patent and making pazt of the-sama To all 'whom/inlay concern: p

Be itknown that LTHMAS S. HA LL,`of Stamford,

vFairfield county, Connecticut, have invented a new and improved Electric Alarm; and I do herebydeclare that the bllowing is a t'nll, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had tothe accompanying drawing forming part of this specification.

Figure 1 represents a i'ront or face view et' my iniprored electric alarm.

Figure 2 is a top or edge view of the same. Similar lettersot reference indicate corresponding parts. i Y

This il'ivention relates to an improvement in the devices for operating thehammer of an alarmfbell by the action of an electric current and of spring-power.

,lhe invention consists in the application ot a system of springs `arranged alongside of each other, and

acting against a plate arranged on ,the armature and proiectingfrom the sides of the same.

Whenthe hammer is attracted toward the electromagnet, the electric circuit `is broken, and it is then drawn vup against the aforesaid system of springs, which 1s provided to act on the broad surface of the projecting-plate to produce permancncy o t" action and.V

reliability.r

When the armature has been elevated theclectrie current is re-established, and the electro-magnet draws it down, it rbc-ing aided byl the aforesaid system ot' springs. 'lhus'rapid vibrating mot-ion is imparted to the hammer to cause itto strikeagainst a bell, there- .by .producing the required alarrn'.l

The springs heretofore used were apt to get out of order and entirely unreliable, and alarms could never be made to'operate for a considerable length of time.

By Vthe use of my system `et' springs all these defects i are entirely overcome.

connected witha wire; F, of a battery.

, B `1s the hemmen-having a spring-shank, C, which .A in the drawing represents' the electro-magnet,

yas described.'

" `Vitnessesz FRANK Bnocnnnr, A SoLoN C. linnen.

A wire, H, extends from the fastening-pin I) 'of thel hammergshank to the other pole of the battery, or to the ground, as the case may be.

vThe lower ends of the spring plates (l are opposite a plate, I, which is as wide as the springs` G, to be acted upon by them.

The operation is as follows:

\Vhen the armature is on the electro-magnet, as in, fig. 1, the current through lthe wire F is-interruptel,

as the parts G and I are out of contact. y The spring shank C vwill then elevate the armature -and raise thehammer, but. at the moment in which ,the parts G and I touch, the current is established through G, I, E, C, and H, with the wire F, and the strong electro-magnct, combined with the weight of the hammer and with the repelling-power of the spring plzitesG, causes the hammer to move down with much greater force than it moved up, and to strike-the-gong or bell J. When down,rthe current is interrupted, and the hammer raised again, as aforesaid. lhus rapid' motion is i'i-npart-ed to the hammer, and it is caused to strike the bell with greater force than could be produced by. any other electric alarm.

Having thus described niy invention, What I claim as new, and desire to secure by Let ters Patent, is- A .The combination of the system of springs G G,

transverse har I, armature E, electro-magnet A A, with coilducting-wires, all constructed and arranged THOMAS s. HALL, 

